Some commercially available 3D printers, such as the ProJet™ 3D Printers manufactured by 3D Systems of Rock Hill, S.C., use inks, which are also known as build materials, that are jetted through a print head as a liquid to form various 3D objects, articles, or parts. Other 3D printing systems also use an ink that is jetted through a print head or otherwise dispensed onto a substrate. In some instances, the ink is solid at ambient temperatures and converts to liquid at elevated jetting temperatures. In other instances, the ink is liquid at ambient temperatures. Moreover, in some cases, the ink can be cured following dispensing and/or deposition of the ink onto the substrate.
Other 3D printers form 3D articles from a reservoir, vat, or container of a fluid ink or build material or a powdered ink or build material. In some cases, a binder material or a laser, digital light processing (DLP) source, or other source of energy is used to selectively solidify or consolidate layers of the ink or build material in a stepwise or layer-by-layer fashion to provide the 3D article.
Inks for 3D printing systems can be used to form a variety of articles for a variety of applications, including in a manner described hereinabove. However, some inks for 3D printing systems include (meth)acrylates as a primary curable material. Such inks may provide high printing resolution but may provide printed 3D articles having limited toughness. Other inks may provide both high resolution and high toughness but may suffer from the presence of one or more toxic or non-biocompatible materials. Therefore, there exists a need for improved inks for 3D printing, including inks that can provide a combination of desirable properties, such as high printing resolution, high toughness, reduced toxicity, and reduced skin sensitization or irritation of a printed 3D article.